Ad agencies have never really been a major part of the world of local online advertising. Apart from some geotargeting for their national and regional clients, they haven’t paid much attention to the many opportunities in local (geotarget banners, local search, couponing, directory and social).

Where there has been agency support, it has been largely on the certified marketing rep (CMR) side that is moving Yellow Pages/directional media dollars around to IYPs and other local “service” media. Companies like TMP’s 15miles and Wahlstrom have done well with this, as have more broadly configured third-party resellers/SMB engagers such as ReachLocal, Yodle, WebVisible, Orange Soda and Clickable.

Other groups, such as AdReady and PaperG, have acted as agencies for clients as they provide local “versioning” for them. Best Buy, for instance, creates different ads in Phoenix than in Miami. AdReady does a lot of versioning work with major clients such as Alaska Airlines. Vertical ad networks such as Adify have also gone into geo-targeting, as have media placement services companies such as Centro, which has worked with mega-advertisers such as GM on their local initiatives.

Recently, however, we’ve been seeing ambitious local initiatives at several of the large agencies. From what we can tell, the initiatives have been spurred from the client side, as national and regional clients have watched local’s momentum — or should we say “Geomentum.” Geomentum is a division of MediaBrands, which itself is owned by InterPublic Group, the third-largest advertising agency holding company. It has a nine-person leadership team, and can also draw off of MediaBrand resources.

We talked with new Geomentum President Lisa Bradner, who most recently served as a Forrester analyst. Bradner told us the problem has always been that it is so much easier to buy national. Local provides all kinds of insights and understanding about clients. But the challenge is to make it scale, she says.

Her efforts will focus on helping people understand the granular research on how/where to spend local. It is a combination of testing and measurement, she says. Whatever happens, advertisers are cutting newspaper spending, and they’re looking for new ways to reach people locally. Verticals with a strong local component such as retail, financial services and insurance will each do well out of the gate, she suggests. Consumer packaged goods and pharmaceuticals also have a local component, but “they’ll be slower to get there.”

What many advertisers want to know is how they can effectively localize their advertising from market to market — an effort that has been worked on intensively by specialists, such as Gannett’s ShopLocal. “Walgreens might lose sales in Poughkeepsie for different reasons than Santa Monica,” says Bradner.

The key is to “take it below the DMA level,” says Bradner. “You want to target the great white space between 1:1 and the DMA,” something that Bradner dubs “one to some.”